7 ms·

Any language is a shell script if you're brave enough: https://en.wikipedia.org/wiki/Shebang_%28Unix%29 https://en.wikipedia.org/wiki/Shebang_%28Unix%29

b-kf 3mo ago
Exactly #!/usr/bin/tcc -run #include <stdio.h> int main(int argc, char **argv) { printf("Hello from C!\n"); for (int i = 1; i < argc; ++i) printf("argument %d: %s\n", i, argv[i]); return 0; } And ready is your cscript :) $ chmod u+x cscript && ./cscript hello world Hello from C! argument 1: hello argument 2: world (I can't even articulate why I love it so much that this works)
- xixixao 3mo ago
  Can you change the current working directory? If not, it's not a shell script.
  - b-kf 3mo ago
    Obviously it's not a shell script, it's still C. It's fun though and being able to freely specify an interpreter/execution path using a shebang has led me to write some useful little command line utilities in unlikely programming languages over the years. That said, not sure why changing the working directory would be the litmus test. A C program can change its own working directory just as easily as an ordinarily executed bash script? $ cat bscript.sh && echo "---" && ./bscript.sh #!/usr/bin/bash cd testdir/ ls --- dummyfile in C you can change dir easily via `chdir()`[1] $ cat cscript && echo "---" && ./cscript #!/usr/bin/tcc -run #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main(void) { if (chdir("testdir") == -1) { perror("chdir"); return EXIT_FAILURE; } execlp("ls", "ls", (char *)NULL); perror("execlp"); return EXIT_FAILURE; } --- dummyfile [1] https://www.man7.org/linux/man-pages/man2/chdir.2.html https://www.man7.org/linux/man-pages/man2/chdir.2.html If you meant somehow changing the parent shell's directory an ordinary bash script doesn't do that either
  - zbentley 3mo ago
    Presumably you can call chdir(2) from the C code? Or did you mean change the directory of the calling shell (in which case, executable shell scripts written in Bash and friends can’t do that either).
    - wavemode 3mo ago
      Well, you can "source" a script, so its effects persist in your current shell session. That's a feature of the script and your shell sharing the same language.
      - zbentley 3mo ago
        Sure, but “shell scripts” as an (admittedly imprecise) term usually imply separate executable files, not shell libraries/functions that are sourced.
      - freehorse 3mo ago
        Then it seems that what you want is running a repl of your chosen language rather than shell/"executable" scripts.
  - ivanjermakov 3mo ago
    Of course you can. How do you think `cd` utility is implemented?
    - xigoi 3mo ago
      cd is a shell built-in, not a script.
hack1312 3mo ago
Can go one step further and define a custom binfmt like was done here https://blog.cloudflare.com/using-go-as-a-scripting-language-in-linux/ https://blog.cloudflare.com/using-go-as-a-scripting-language...
- rsyring 3mo ago
  Didn't know about the binfmt_misc hooks in Linux. Good read! Thanks for sharing.

b-kf 3mo ago

Exactly #!/usr/bin/tcc -run #include <stdio.h> int main(int argc, char **argv) { printf("Hello from C!\n"); for (int i = 1; i < argc; ++i) printf("argument %d: %s\n", i, argv[i]); return 0; } And ready is your cscript :) $ chmod u+x cscript && ./cscript hello world Hello from C! argument 1: hello argument 2: world (I can't even articulate why I love it so much that this works)

xixixao 3mo ago
Can you change the current working directory? If not, it's not a shell script.
- b-kf 3mo ago
  Obviously it's not a shell script, it's still C. It's fun though and being able to freely specify an interpreter/execution path using a shebang has led me to write some useful little command line utilities in unlikely programming languages over the years. That said, not sure why changing the working directory would be the litmus test. A C program can change its own working directory just as easily as an ordinarily executed bash script? $ cat bscript.sh && echo "---" && ./bscript.sh #!/usr/bin/bash cd testdir/ ls --- dummyfile in C you can change dir easily via `chdir()`[1] $ cat cscript && echo "---" && ./cscript #!/usr/bin/tcc -run #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main(void) { if (chdir("testdir") == -1) { perror("chdir"); return EXIT_FAILURE; } execlp("ls", "ls", (char *)NULL); perror("execlp"); return EXIT_FAILURE; } --- dummyfile [1] https://www.man7.org/linux/man-pages/man2/chdir.2.html https://www.man7.org/linux/man-pages/man2/chdir.2.html If you meant somehow changing the parent shell's directory an ordinary bash script doesn't do that either
- zbentley 3mo ago
  Presumably you can call chdir(2) from the C code? Or did you mean change the directory of the calling shell (in which case, executable shell scripts written in Bash and friends can’t do that either).
  - wavemode 3mo ago
    Well, you can "source" a script, so its effects persist in your current shell session. That's a feature of the script and your shell sharing the same language.
    - zbentley 3mo ago
      Sure, but “shell scripts” as an (admittedly imprecise) term usually imply separate executable files, not shell libraries/functions that are sourced.
    - freehorse 3mo ago
      Then it seems that what you want is running a repl of your chosen language rather than shell/"executable" scripts.
- ivanjermakov 3mo ago
  Of course you can. How do you think `cd` utility is implemented?
  - xigoi 3mo ago
    cd is a shell built-in, not a script.

hack1312 3mo ago

Can go one step further and define a custom binfmt like was done here https://blog.cloudflare.com/using-go-as-a-scripting-language-in-linux/ https://blog.cloudflare.com/using-go-as-a-scripting-language...

rsyring 3mo ago
Didn't know about the binfmt_misc hooks in Linux. Good read! Thanks for sharing.